Synthesis and characterization of two-stage curing reactive bio-based polymers

Abstract

Two-stage curing reactive bio-based polymers network namely, poly(octanediol-co-dodecanedioate-co-citrate-co-itaconate) (PODCI) were successfully synthesized using 1,8-octanediol, citric acid, itaconic acid and 1,12-dodecanedioic acid. In the first curing stage, a prepolymer of PODCI was thermally crosslinked. At a later time, a second curing was completed thru photo-initiated free-radical polymerization. Here, we discovered that permanent shape of the thermally crosslinked PODCI was successfully reconfigured by application of second stage curing. The molar ratio of itaconic acid (IA) to citric acid (CA) and time of photo-curing was varied. Based on XRD analysis, the polymer crystallinity of the bio-based polymer decreased with time of photo-curing. The swelling ratio of bio-based polymer decreased from 2750 % to 250 % as soon as completion of second stage curing. PODCI existed as a semi-crystalline polymer with a melting transition temperature of 40.2 ℃. Also, PODCI exhibited excellent shape memory properties with shape recovery by nearly 100%.